Radiosignaling apparatus



RADIOSIGNALING APPARATUS.

' APPLICATION FILED JULY 12, 1918.

1,356,752. Patented 001;. 26,1920.

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RADIOSIGNALING APPARATUS.

APPLICATION FILED JULY 12, 1918.

1 ,3563752. Patented Oct. 26, 1920.

5 SHEETS-SHEET 2.

R. A. WEAGANT AND-F. N. WATERMA/N.

RADIOSIGNALING APPARATUS.

APPLICATION FILED JULY 12, 1918.

1,356,752. Patented Oct. 26,1920.

4 5 SHEETS-SHEET 3.

R. A. WEAGANT AND F. N. WATERMAN.

RADIOSIGNALING APPARATUS.

APPLICATION FILED JULY I2, I918.

1,356,752. Patnted Oct. 26,1920.

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I A M I Qwmntz' R. A. WEAGANT AND F. N. WATERMAN. RADIOSIGNALINGAPPARATUS.

APPLICATION FILED JULY 12, 1918.

Patented Oct. 26, 1920.

5 SHEETS-SHEET 5- UITED STATES IROY ALEXANDER WEAGANT, OF NEW YORIL N.Y., AND FRANK N. WATERMAN, OF

SUMMIT, NEW JERSEY, ASSIGNORS, BY MESNE ASSIGNMENTS, TO RADIO CORPORA-TION OF AMERICA, A CORPORATION OF DELAWARE. I

RADIOSIG-N'ALING APPARATUS.

Specification of Letters Patent.

Patented Oct. 26, 1920.

Application filed July 12, 1%}18. Serial No. 244,563.

Union, State of New Jersey, have invented central receiving apparatus.

certain new and useful Improvements in Radiosignaling Apparatus, ofwhich the following 15 a specification accompanied by drawings.

This invention relates to radio signaling apparatus, but moreparticularly to receiving apparatus employing a plurality of antennee inwhich the effects of static disturbances are balanced out at thereceivingstation while the signals are retained in accordance. with thediscoveries of Roy A. Weagant and the methods and apparatus basedthereon disclosed in his co-pending applications' Serial Nos. 157,594and 181,458.

In the applications referred to are disclose-d loop antennae in the formof cages separated by an appreciable fraction'of a wave length andconnected by long leads to the V In practical reception, especially withvery long wave lengths, these long leads are found to'introduce'certaindifliculties, most of which are successfully overcome by the apparatusdisclosed in R. A. Weagants co-pending application, Serial No. 244,562which includes adjusting and tuning means at the loops or cages as wellas at the receiving station;

Use of the loop and lead antenna systems, while admirably operative, isinconvenient and has indicated that much of theinconvenience probablylies in the fact that the The primary object of the present invention isto do away with the long leads and devise means for operating inaccordance with R. A. WVeagants basic discoveries, which will obviatethe inconveniences due to the leads.

We have discovered that the inconveniences herein referred to may belargely avoided by means of antennae which, of themselves, are soconstructed as to have substantially uniformly distributed 'or gradedconstants, thereby making it possible to either avoid reflection pointsaltogether or to arbitrarily introduce them at 'will and at selected orexperimentally determined positions, or at calculated positions. lVehave found that antennae in the form of greatly elongated loops of anydesired vertical height extending substantially horizontally in oppositedirections from the station in the general line of transmission and having their planes substantially vertical, avoid many of theinconveniences due to the use of forms. 7 K

In accordance with our present invention,

the signal energy collected by the antennae is rendered available in thestation for the plurality of turns arranged in various purpose ofdetection and utilization, and 1 another important advantage of thisinven:

tion resides in the fact that all offthe adjusting and tuning may becompletely controlled by means of adjustable elements 10- cated at onepoint; that is, at the-'central-re-' ceiving station itself, where thereceiving apparatusis located, and this has been found to. be true,.evenwith an effectiveantenna separation as great as one-half wave length forvery long waves, many thousands of meters long. By effective separationin this instance, we mean the distance between the centers of the loops,for the loops must terminate at a distance farther away from the stationthan in the case of cage antennae for the effective separation, but 1nthe case of the loops, no operators are needed at the far ends.

We have found that with antenna in the form -of loops substantially asherein described, and illustrated in the accompanying drawings in someof their forms as used by us we are enabled to balance out the staticand retain the signals in accordance with the discoveries and basicprinciples of operation disclosed in the co-pending applications, SerialNos. 157,594 and 181,458 referred to. In the drawings Figure 1 is adiagrammatic representation of circuits and apparatus embodying theinvention in which two greatly elongated, horizontally extending loopantennae are shown.

Fig. 2 is a modification of Fig. 1 in which line inductances are shownconnected in the loops.

Fig. 3 is a view similar to Fig. 2 showing a modification of thecircuits=at the receiv-' ticularly to Fig. 1, the outline represented atA indicates a receiving station or receiving house in which thereceiving apparatus is located. A plurality of antennae B, in thisinstance a pair of antennae, in the form of elongated loops, which maybe of any desired dimensions, are .shown extending substantiallyhorizontally in opposite directions from the station A, These elongatedloops are shown with dotted portions in their length to indicate thatthe loops are very much longer, in proportion, than rep 7 resented owingto the limits-of the sheet on which they are drawn. The loops preferablyextend in the same, or substantially parallel, planes in the generaldirection of reception and the wires forming the loops may beconveniently supported in any suitable manner on stakes or poles,depending upon the dimensions of the loops. In Fig.

I. 1 for instance, stakes 0 approximately four feet in length areindicated, and the loops are approximately three and one-half feet invertical height or width. The vertical dimensions of the loops are thusrelatively small compared to their length, which should be equal to anappreciable fraction of the wave length of the signal waves to bereceived. We have constructed such the loops.

loops each with a length of over 9000 feet,

making the total length between the outer 18,000 of the is apa 6000 endsof .the loops something over feet, so that the effective separationloops measuring from the centers, proximately a half Wave length formeter wave.

The loops, as shown in Fig. 1, may consist of wire or other suitableconductors D strung or suitably fastened to, but preferably insulatedfrom the stakes C. In the form of the invention shown in Fig. 1 it is tobe understood that the lower length or I wire E of each loop issupported near the ground while the upper length or wire F is preferablylocated substantially vertically over the wire E. i

The inner ends of the loops as shown are preferably brought into thereceiving station by means of short leads of lead sheathed cable G whichmay be from 50 to 100 feet in length so that the length of the leads istrivial compared to the length of These short lengths of lead cable seemto have a beneficial effect in reducing" the electro-magnetic orelectrostatic coupling between the loops and the receiving apparatus.

At the receiving station or house A we provide any suitable form ofreceiving apparatus for balancing out the static while retaining thesignals and for illustrative purposes we have shown a oniometer G havingthe stationary coils and the movable coil J pivoted at K, although weare not to be understood as limiting ourselves to agoniometer, forvarious forms of receiving apparatus or coupled circuits may beprovided. A- goniometer is however found to be a suitable and convenientinstrument for. our purposes.

The wires from the cables G as shown are connected to the stationarycoils H of the gpniometer through the reversing switches becauseit hasbeen found that there is apparently a best relation between the leadsand the receiving apparatus, and it is desirable to be able to reversethe connections of the leads to the receiving apparatus as dc sired. Theleads are provided with the tuning inductances L, and variablecondensers P are shown connected in series with the fixed goniometercoils H. A variable condenser P' is also shown in series with themovable goniometer coil J.

Suitable receiver circuits including a three-element vacuum valve V areshown coupled to the circuit Q, which is, connected through reversingswitch R, to the goniometer coil J, because it has been found that it isdesirable to be-able to control the connections between the receivercircuits and the goniometer. The circuit Q also preferably includes theloading inductance S and nected to the oscillatory circuit a?) and theValve has, as shown, the-usual plate circuit '0, d, e, f, and in-addition the oscillatory circuit 0, g, h, 7, although any suitable ordesirable circuits may be used.

By suitable adjustment of the apparatus the effects due to staticdisturbances neutralize and balance out, while the effects due to thesignals combine to produce a resultant current in the receivingcircuits.

" The elongated loop antennae, such as illustrated in Flg. 1, have theirconstants so uniformly distributed as to avoid natural revarying fromabout one and one-half feet to about sixteen feet, and these loops havebeen arranged with varying elevations of 5f.--='tl1e lower E from apoint close to the ground up' to about twelve feet from the ground, andall with good results. As far as our observations have gone, the bestrebetween the upper and lower wires EF- sults appeared to be obtainedwith the wider separation of the wires E andF. Our observations alsoindicate that the lower wires or lengths E of the loops should not be soclose to the ground asto give high damping.

The actual vertical separation between the Wires E and F may however beanything desired.

Since the effective separation-of two such oppositely extended elon atedantennae is equal to the distance betv een their centers, each loop mustbe one-half wave length in length, in order, to obtain a separation of ahalf wave length. The natural wave length of such an antenna is verygreat and to control effectively its mode of vibration and enable it'totune effectively below its natural period, we have found it desirable tointro- 'duce preferably fixed concentrated line inductances such asshown at U in Fig. 2.

The antennae shown-in Fig. 2 are like those shown in Fig. 1 with theexception of the line inductances U. As an example,'in

an antenna of Fig. 2, havin a length of approximately 3600 feet, we avefound that a line inductance U of the order of 5 millihenrys isadvantageous for wave lengths between 2000 and 8000 meters, and in aloop approximately 9200 feet long, a value of inductance U of the orderof 32 milli-henrys has proved effective. There appears to besubstantially nothing critical about these values, however, although foreach loopand wave length there is a most desirable order of magnitudefor the line inductances.

These line inductances U do notappear to act as tuning elements in theordinary sense, but rather seem to determine the mode of vibration ofthe loop and the location of the nodes and anti-nodes of current. Theoscillation is apparently at multiples of the fundamental frequency andseemingly at even harmonics, but all attempts to find an exact analysisof the mode of vibration have thus far failed togive conclusive results.

In our tests thus far made the best results have been attained when theline inductance U was located at or near the middle of the top wire F ofthe loop, and a change of location from this middle point resulted in areduction in the strength of a signal. In-

.stead of the line inductances U, combinations of inductance andcapacity may be used, or the wire-may actually be opened (as in Figs. 4;and 6) and good results in eliminating static and preserving the signalmay thus be attained.

. As we have indicated, the function of the line inductance U in the topleg or wireof the. loop is to enablethe tuning to be accomplished; Thereason for the location of the line inductance at a particular place inthe length of the loop, which, however, is variable with othervariations in the-circuits, is to bring about a current distributionsuch that the tuning elements inserted in the station end of the loopmay haveproper effect. 7

With loop. antennae wave length long, we have found that the loops tunebest with parallel tuning, that is,

'With the condensers P (Fig. 2) in parallel across the leads; and wehave also found that the tuning inductances L under such conditionsshould be inserted as shown in Fig. 2 in the opposite leg of the loopfrom the line inductance U. With the exception of the location of thecondensers P the circuits of the receiving apparatus in Fig. 2 areindicated the same as Fig. 1, although the receiver circuits are notindicated, for simplicity.

Fig. 3 shows diagrammatically circuits and apparatus at the receivingstation for both series and parallel tuning. The goniometer coils H areprovided with ordinary switches W shown in Fig. 3 in closed positionbecause the condensers P are shown connected in parallel across theleads between the points 0 p and q 7' through the double throw switches8. When these switches a are thrown to the opposite position, theconapproximately a'halfdensers P will be connected in series with thegoniometer coils H and then the-knife switches W should be open. In Fig.3, inductances L and L, are shown at the station in both leads from theloops and either or both of these inductances may be used as desired,depending upon the conditions.

The leads are brought to the reversing switches O and from thence thecircuits are connected to the goniometer coils H so that the relation ofthe leads to the receiving apparatus may be reversed as desired.

In Figs. 4 to 8 inclusive A represents. the receiving station orreceiving house in which the receiving apparatus is located, it beingunderstood that receiving apparatus substantially like that indicated inFig. 3,

p for instance, will be used in the house. Figs.

- matically and may be of 4 to 8 inclusive illustrate-different forms ofloop antennae which We have used.

In Fig. 4 the elongated loop antennae 2 are open at the ends 3, it beingunderstood that'the antennae are illustrated diagramsions. f

Instead of actually opening the loops, a condenser 4 may be inserted ateach end,'as in Fig. 5'. In either the case of Fig. 4 or of Fig.

5-the antennae appear to act as loops closed through the capacities ofthe wires to one another. They act as loops of indeterminate length, theeffective length for a given actual length depending upon the separationof the wires. i

' In Fig. 6 the loop antennae 5 are shown opened in the upper legs atthe point 6, and

these'openings may be at any points desired instead of at the centers,as shown. With all of these forms of' antennaewe have had good resultsin balancing out static and receiving signals. In Fig. 7 the loops 7 areshown supported on high poles 8, about twenty feet high, the

lower leg 9 of each loop being approximately twelve feet. from theground in the constructions with which we haveactually worked.

In Fig. 8 the loops 10 are shown having a vertical separation of thelower and upper stood as indicating that any one form is better than allothers for all purposes in the present state of our knowledge.

Figs. 9 to 14 show different formsof loop antennae having a plurality ofturns throughout the whole or a portion of their length. Fig.9'illustrates a construction of elongated low loop antennae in which alocalized inductance 15 is purposely included by the construction of theloop itself and this maybe located at any desired point in any suitabledimen- I Lemma .the length. Fig. 10 is like Fig.8, except that the loop16 is shown with a larger vertical dimension.

Figs. 11 and 12 show the loops 17 and 18 having the plurality of turnsat their farther ends instead'of at the middle.

Figs. 13 and 14 show low and high loops plurality of turns for a givenoverall length. Thus'to attain an effective separation of one-half wavelength with any of the forms shown in Figs. 15 to 18, it seems onlynecessary to have a length for each antennae of something less thantheorder of three-fourths the length re quired in the case of theparallel sided loops.

In Fig. 15 the loops 21 are in the form of right angled triangles havingtheir bases 22 vertical and about twenty-elght feet high, although thisheight may be varied as desired and may be very much higher. The apex 23of each loop is adjacent the station'A and the wires are preferablycarried into the receiving house through theshort lengths .of lead cableG. Each loop 21 was about 3600 feet long in our actual work, althoughthe length may be made anything desired. In Fig. 15 the lower wire 24 ofeach loop is shown substantially parallel to the ground and the loopsare supported on suitable poles Fig. 16 shows the loops 25 in the formof isosceles triangles,'while Fig. 17 shows the loops 26 havin theirupper wires 27 substantially paral e1 to the ground. In Fig. 18 theupper and lower wires of the loops are shown supported on the poles insuch manner that the sides of the loops are in the form of curvesinstead of straight lines.

' We claim and desire to obtain by Letters Patent, the following:

1. At a radio transmission receiving sta tion, a plurality of antennaeextending sub-' stantially horizontally in opposite directions, theeffective separation of said antennae for the reception of signal wavesbeing an appreciable fraction of a wave length, and receiving apparatusassociated with said antennae for utilizing the signal waves, includingmeans for balancing out the currents due to static disturbances whileretaining the signals.

2. At a radio transmission receiving station, a plurality of antennaeextending substantially horizontally in opposite directions, theeffective separation of said antennae for the reception of signal wavesbeing an ap-. preciable fraction of a wave length, means for tuning'theantennae to the incoming signal, and receiving apparatus for utilizingthe signal waves, including means for balancing out the currents due tostatic disturbances while retaining the signals.

3. At a radio transmission recelving station, a plurality of elongatedloop antennae extending substantially horizontally in opto the incomingsignal, and receiving apparatus for utilizihg the signal waves,including means for balancing out the currents due to staticdisturbances while retaining the signals. 7

4:. At a radio transmission receiving station, a plurality of loop.antennae extending from the receiving station in opposite directions insubstantially the general direction of transmission and having arelatively small vertical dimension compared to a length equal to anappreciable fraction of the wave length of the signal wave to bereceived, and receiving apparatus for balancing out the static whileretainingthe signals.

5. At a radio transmission receiving station, a plurality of loopantennae extending from the receiving station in opposite directions insubstantially the general direction of transmission and having arelatively small vertical dimension compared to a length equal to anappreciable fraction of the wave length of the signal wavesto bereceived, and receiving apparatus for balancing out the static whileretaining the signals, said loops being connected to the recelvingapparatus by means of leads substantially trivial in length as comparedwith the length of the loops.

6. At a'radio transmission receiving station, a plurality of elongatedloop antennae extending substantially horizontally in oppositedirections, receiving apparatus, and leads substantially trivial inlength as compared to the length of the loops connecting said loops tothe receiving apparatus.

7 At a radio transmission receiving station, a plurality of elon atedloop antennae extending substantially orizontall in oposite directions,said antennae being free rom natural reflection points, and receivingapparatus forutilizing the signal waves, including means for balancingout the static while retaining the signals.

8. At a radio transmission receiving sta tion, a plurality of elongatedloop antennae extending substantially horizontally in opositedirections, said antennae being free 10m natural reflection points,means for tuning the antennae to the incoming signal,

and receiving apparatus for utilizing the signal waves, including meansfor balancing out the static while retaining the signals.

9. At a radio transmission receiving station, a plurality of loopantennae extending substantially horizontally in opposite directionsfrom the station, said antennae being free from natural reflectionpoints, means for controlling the mode of vibration of said antennae,and receiving apparatus for utilizing the signal waves, including meansfor eliminating the interference due to static disturbances. I

10. At a radio transmission receiving station, a plurality of loopantennae extending from the receiving station in opposite directions insubstantially the general direction of transmission and having arelatively small vertical dimension compared to a length equal to anappreciable fraction of 1 the wave lengthof the signal waves to bereceived, means for controlling the mode of vibration of said antennaein response to received, signals, and receiving apparatus for balancingout the static while retaining the signals.

11. At a radio transmission receiving station a pair of loop antennaeeach having one terminus adjacent to the station, and the oppositeterminus at an appreciable fraction of a wave length away from thestation,

and receiving apparatus at the station for balancing out static whileretaining the signals. 4

12. At a radio transmission receiving -sta-. tion, two loop antennaelocated in substantially the general direction of transmission, andreceiving apparatus located between them, said antennae being free fromnatural reflection points," means located in one length of each loop forcontrolling the mode of vibration of the loops, and tuning means at thestation located in the other length of each loop;

13. At a radio transmission receivingstation, two loop antennae locatedin substantially the general direction of transmission, and receivingapparatus located between them, said antennae being free from naturalreflection points, means located in the top length of each loop forcontrolling the mode of vibration of the loops, and tuning means at thestation located in the otherlength of each loop. Y

14. At a radio transmission receiving station, a plurality of loopantennae extending turbances, and means for tuning the antennae out-thestatic while retaining the signals,-

and means for tuning the antennae to the incoming signal.

16. At a radio transmission receiving station, two loop antennae locatedin substantially the general direction of transmission,

and receiving apparatus located between them, said antennae being freefrom natural reflection points, means fdfcontrolling the mode ofvibration of said loops, and means for tuning the antennae to theincoming signal.

17. At a radio transmission receiving station, a plurality of elongatedloop antennae, each having aplurality of turns and extendingsubstantially horizontally in opposite di-. rectiofls from the receivingstation, receiving apparatus located between said loops, for utilizingthe signal waves, including means for balancing out static whileretaining the signals, and leads substantially trivial in length ascompared to the length of the loops connecting said loops to thereceiving apparatus.

18. At a radio transmission receiving station, a plurality of elongatedloop antennae, each having a plurality of turns throughout at least aportion of their length, said antennae extending substantiallyhorizontally in opposite directions from the receiving station,receiving apparatus located between said loops, for utilizing the signalwaves, in-' cluding means for balancing out static while retaining thesignals, and leads substantially trivial in length as compared to thelength of the loops connecting said loops to the receiving apparatus. v

19. At a radio transmlsslon receiving station, a comparatively low loopantenna ex- I tending horizontally, the area of Which, per

unit length measured horizontally, increases as a function of thedistance from the station in the direction of propagation;

20. At a radio transmission receiving station, a low loop antennaextending horizon: tally having a length in a horizontal direction equalto an appreciable fraction of a wave length, the area of which loopperunit.

length increases as a function of the-distance from the station.

21. At a radio transmission receiving station, a pair of loop antennaeextending substantially horizontally in opposite directions from thestation, the area of each loop, per unit length, increasing as afunction of the distance from the station,

22. At a radio transmission receiving station, a pair of loop antennaeextending substantially horizontally in opposite directions from thestation, each loop having a length equal to an appreciable fraction of awave length, the area of each loop, per unit length, increasing as afunction of the distance from the station. a

23. At a radio transmission receiving station, a pair of loop antennaeextending substantially horizontally in opposite directions insubstantially vertical planes, the upper,

paratus located between said loops and arranged to balance out impulsesof like phase and to combine cumulatively impulses of different phase.

24. At a radio transmission receiving station, a pair of loop antennaeextending sub stantially horizontally in opposite directions insubstantially vertical planes, the upper and lower sides of said loopsdiverging away from one another, and receiving apparatus located betweensaid loops for balancing out the currents due to static disturbanceswhile retaining the signals. 4

In testimony whereofwe have'signed this specification in the presence oftwo subscribing witnesses.

ROY ALEXANDER- VVEAGANT. FRANK N. WATERMAN. Witnesses:

HERBERT G. OGDEN, M. H. PAYNE.

